In 1984 trees of `Starkspur Supreme Delicious' apple (Malus domestica Borkh) on 16 rootstocks were planted at 30 sites in North America according to guidelines established for cooperative testing by the North Central Regional Cooperative Project (NC-140). Tree loss and root suckering in the Maine planting have been low, similar to that of other sites. Tree size in Maine is smallest amoung all sites after seven seasons. Trees on Budagovsky 9 (B.9) rootstock were the most precocious, producing significantly higher flower numbers and yield in the third year. Other precocious root-stocks in this planting included C.6, M.26EMLA, M.7EMLA and P.1. After seven years, B.9, C.6 and M.26EMLA were the most productive amoung the dwarf trees, and consequently are the most efficient. P.1 and M.7EMLA were the most productive amoung the more vigorous stocks. This trial will be conducted for 3 more seasons, however it appears that B.9, C.6 and P.1 may have potential as rootstocks for commercial apple orchards in New England.
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